ESP8266 Community Forum

- Tue Dec 24, 2019 5:25 pm #85039 Hi,
I trying to use 3 1.2V AA batteries to run my NodeMCU. However, they run out fairly quickly. I was thinking of changing out the AMS1117 voltage regulator out with another one. I've been looking at the HT7333 and XC6206, but not sure if these are the best options. Also how would I go about installing these on the board?
Thank You.

- Mon Dec 30, 2019 10:39 pm #85107 Neither of those is a direct pin-for-pin replacement for the SOT-223 AMS117; the Vin and Vout pins are swapped between the AMS and the other two, so you'd have to get creative.

Also, the power tab on a SOT-223 or SOT89 is usually connected to the center of the three pins, so it's likely also swapped Vin vs. Vout for AMS compared to the other two. That makes a non-direct swap even harder, as you don't have any place to dump the waste heat. None of the 3 data sheets spec the pinout of the power tab, but it's nearly always the middle one of the other 3 pins due to the frame inside.

The Torex doesn't even spec the quiescent current, so I presume it's pretty high, maybe as high as the AMS. I doubt that would be worth the effort.

I've used the Holtek parts before and they're pretty good, but hard to get unless you're in Taiwan or China.

You're better off trying to find different ways to reduce power in your program. Deep sleep offers the lowest power when you're not doing anything else, but it's still on the order of 60-80uA if I remember correctly.

- Tue Dec 31, 2019 10:15 am #85115 The NodeMCU is great for development and is fine for mains powered deployment. However, it's not really a good choice for battery powered deployment if you want a decent battery life. Not only is the regulator drawing more quiescent current than desirable but the USB to serial chip is also drawing a significant current. So even if you are using deep sleep to try extend battery life then these other currents will still drain the battery fairly fast.

If you want to maximise battery life then you are better off deploying a raw module like the ESP-12F. This means you get to choose a low quiescent regulator as well. Obviously it is trickier to download code to these but there are good solutions and if you use OTA then it only as to be done once.

- Sat Jan 04, 2020 3:27 pm #85158 HT7327-1 seems a good choice for a ESP12E/F. The current drops from 35µA down to 20µA using 2.7V instead of 3.3V for the entire board, the esp module itself uses probably only 13-15µA